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Strains of Eupenicillium crustaceum and related fungal species produce aflavinines and antiinsectan metabolites from the ascostromata. The antiinsectan activity of E. crustaceum NRRL 3332 generate the aflavinine analogs 10,23-dihydro-24,25-dehydroaflavinine and 10,23,24,25-tetrahydro-24- hydroxyaflavinine. E. reticulisporum NRRL 3446 produces 10,23-dihydro-24,25-dehydroaflavinine and pyripyropene while E. molle NRRL 13062 produces aflavinines and macrophorins.

Two antifungal metabolites stachybotrins A and B were obtained from ethyl acetate extracts of liquid cultures of Stachybotrys sp. (CS-710-1). Acetylation of stachybotrin A yielded a triacetate with two carbons bearing free OH groups as analyzed in 1H NMR spectrum. Stachybotrin B yielded a diacetate whose NMR data was almost similar to A. The differences between the two compounds were the absence of the vinylic CH2OH signal and the presence of a third methyl group singlet.

Silica gel column and reversed-phase high performance liquid chromatographies yield four new antiinsectan metabolites from the sclerotia of the fungus Aspergillus sulphureus. Sulpinines A-C and secopenitrem B belong to the paspaline/penitrem class of pesticide bases. Nuclear magnetic resonance studies and comparison with known penitrems establish the structures of the new antiinsectans. Sulpinine C has a unique ring system that includes an eight-membered-ring lactam. Sulphines A and B and secopenitrem B prove to be potent against the crop pest Helicoverpa zea.

Research was conducted to examine the isolation and characterization of antifungal metabolites yielded by Humicola fuscoatra which prevent the growth of Aspergillus flavus sclerotia. The mycoparasite Humicola fuscoatra Traaen NRRL 22980 was isolated from the sclerotium of A. flavus that was buried for three years in Georgia. Results indicate that H. fuscoatra generates various antifungal agents that are effective against A. flavus.

Gakolanone (3',5'-digeranyl-2',4',6',3-tetrahydroxybenzophenone; 1), a novel benzophenone derivative was isolated from the hexane extract of Garcinia kola Heckel stem-bark along with three known 3-8' linked biflavonoids: 3',4',4'',5,5',7,7'-heptahydroxy-3,8'-biflavanone (2); 3',4',5,5',5'',7,7'-heptahydroxy-4-methoxy-3,8'-biflavanone (3) and 4',4'',5,5',7,7'-hexahydroxy-3,8'-biflavanone (4) from the ethanol extract. The compounds were characterized primarily using 1 D and 2 D nuclear magnetic resonance spectroscopy and mass spectrometry and by comparing with literature. The compounds were subjected to in-vitro alpha-amylase enzyme inhibitory assay using DNSA (3,5-dinitrosalicylic acid) reagent with acarbose used as the standard drug. All the compounds were found to show alpha-amylase inhibitory activities with IC50 of 21.4 ± 1.5, 9.9 ± 0.2, 15.3 ± 2.3, 12.9 ± 2.3 µg/mL respectively. All the compounds exhibited better alpha-amylase inhibitory activities than the standard drug, acarbose (IC50= 38.1 ± 8.3 µg/mL). [ABSTRACT FROM AUTHOR]

The pentane extract of the sclerotia of Aspergillus nomium yields aspernomine, a cytotoxic antiinsectan fungal metabolite. The novel compond possesses a unique ring system and exhibits potent activity against the corn earworm Helicoverpa zea. The compound also exhibits cytotoxicity toward three human solid tumor cell lines. NMR spectroscopic studies at 600 MHz are conducted on aspernomine to determine its structure.

We used a temperature differential assay with the opportunistic fungal pathogen Cryptococcus neoformans as a simple screening platform to detect small molecules with antifungal activity in natural product extracts. By screening of a collection extracts from two different strains of the coprophilous fungus, Amphichorda felina, we detected strong, temperature-dependent antifungal activity using a two-plate agar zone of inhibition assay at 25 and 37 °C. Bioassay-guided fractionation of the crude extract followed by liquid chromatography–mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR) identified cyclosporin C (CsC) as the main component of the crude extract responsible for growth inhibition of C. neoformans at 37 °C. The presence of CsC was confirmed by comparison with a commercial standard. We sequenced the genome of A. felina to identify and annotate the CsC biosynthetic gene cluster. The only previously characterized gene cluster for the biosynthesis of similar compounds is that of the related immunosuppressant drug cyclosporine A (CsA). The CsA and CsC gene clusters share a high degree of synteny and sequence similarity. Amino acid changes in the adenylation domain of the CsC nonribosomal peptide synthase’s sixth module may be responsible for the substitution of l-threonine compared to l-α-aminobutyric acid in the CsA peptide core. This screening strategy promises to yield additional antifungal natural products with a focused spectrum of antimicrobial activity. [ABSTRACT FROM AUTHOR]